Laguna Seca 92db question - McLaren Life
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post #1 of 17 Old 05-24-2019, 12:31 PM Thread Starter
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Laguna Seca 92db question

For those of you who have tracked at Laguna in your 570S: I have a 92db day coming up, where does the 570S with sport exhaust come in on the meter? Is it a lift and short shift situation, or can I hammer it past the sound station?
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post #2 of 17 Old 05-24-2019, 03:46 PM
 
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12C sports exhaust, OEM downpipes was 92.5db at Laguna Seca

Posted number for the 570s with sports exhaust 127db at WOT in high gear.
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post #3 of 17 Old 05-24-2019, 04:24 PM
 
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I would second shardul's comment. Sport exhaust is over 100db at high revs. You may want to "lift" as you approach and go by.

As for the 127db figure, that sounds really high for sports exhaust. I know b/c I was at 110db (5000 RPM) with custom exhaust and sport cats.
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post #4 of 17 Old 05-25-2019, 03:25 AM
 
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127 DB sounds VERY loud to me.
Every 10 DB increase gives a 10X increase in Sound Intensity, and a 2X Perceived Loudness.
So, from 100 DB to 120 Db, the Sound Intensity is 100X, and the Perceived Loudness is 4X as loud.
It's tough at Laguna to beat the system, as the Measuring booth is out of turn 5, accelerating uphill.
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post #5 of 17 Old 05-25-2019, 04:19 AM
 
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I run a 12c with stock exhaust and pass 92db without lifting. 127db is like a fighter jet at full throttle. Like 3000x more intense.
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post #6 of 17 Old 05-25-2019, 05:02 AM
 
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I had to lift AND be in fifth gear to pass at Laguna. My buddy that shared my car with me lifted but stayed in fourth and got us booted from the track. 92 dB day. Good luck.

Kurt
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post #7 of 17 Old 05-25-2019, 05:46 AM
 
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There has been an uptick in meatball flags at Laguna Seca in the last year.

They give 2.4 decibel leeway from whatever the sound restriction is that day. Basically you have 94.4 db before you get flagged on a 92 db day.

What seems to have changed is that 2.4 db leeway ever since Weathertech took over the sponsorship of the track. There just seems to be many more meatball flags then what was in the past.

You'll probably be able to pass on a 92 db day... as long as you don't downshift under the bridge (before or just after and it doesn't echo), and do not create the backfire with the upshift right around the sound station. You might just want to take turn 5 in fourth gear so that you don't create the backfire.
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post #8 of 17 Old 05-25-2019, 08:26 AM
 
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Quote:
Originally Posted by shardul View Post
12C sports exhaust, OEM downpipes was 92.5db at Laguna Seca

Posted number for the 570s with sports exhaust 127db at WOT in high gear.
That's a massive difference - any idea why? The 12C sports exhaust isn't exactly subtle.
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post #9 of 17 Old 05-25-2019, 07:52 PM
 
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The county owns that track and they have been getting noise complaints from the locals. I know I know, the track was there first but it doesn’t matter at this point. The county is cracking down and we just have to adjust.
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post #10 of 17 Old 05-25-2019, 07:55 PM
 
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127 dB from a car is fake news. https://www.chem.purdue.edu/chemsafe...n/dblevels.htm

All i know is my 12c w stock exhaust has never been flagged, but a 650S w sport exh has to lift.
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post #11 of 17 Old 05-26-2019, 07:40 AM
 
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Soooo frustrating.

These days I just search for the >100 (or unlimited) dB days at Seca. I’ve actually kept the stock exhaust on my Gen IV ACR just because of the restrictions at Laguna Seca... it’ll go max 92 dB up the hill on a normal day.

On the plus side, those high dB days are like a reunion of all your racecar buds. Some of my favorite track memories are from running with serious fast/loud cars in the group...


Rich
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post #12 of 17 Old 05-26-2019, 06:10 PM
 
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I dont know if it still works this way but there were a certain number of days/events at certain dB limits. Only About 5 weekends at 102. A few at 96 or so. Lots at 92. One year we (bmws) were racing with Porsche club on 92dB. They vowed to get a 102 weekend—just need to triple the entry fees to cover the extra $50k rental !

Last edited by scottch; 05-26-2019 at 06:13 PM.
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post #13 of 17 Old 05-27-2019, 01:39 PM
 
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Quote:
Originally Posted by scottch View Post
I dont know if it still works this way but there were a certain number of days/events at certain dB limits. Only About 5 weekends at 102. A few at 96 or so. Lots at 92. One year we (bmws) were racing with Porsche club on 92dB. They vowed to get a 102 weekendójust need to triple the entry fees to cover the extra $50k rental !
I think the Hooked on Driving group has a high dB coming soon. Check their website.
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post #14 of 17 Old 05-27-2019, 02:48 PM
 
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Fast toys club has a 102 dB day on June 13th I believe. I was going to register for it the other night.
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post #15 of 17 Old 05-27-2019, 03:35 PM
 
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Hooked on driving on 06/12 is a half day event

Fast toys is open track (no run groups). Mainly novices. Passing (point by or no point by) is only on front straight to bridge before turn 1, turn 4 to 5 and 5 to 6. Not a good idea to go unless you are a novice or intermediate driver.
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